For a variety of reasons it may be necessary or useful to know the location history of a user with varying degrees of certainty. In some instances it may be enough to use the user's stated location (i.e. where the user says he or she is.) For example, location information a user shares with friends or relatives can use stated location. The user, however, user may later wish to view their own location history and see where they actually were, rather than where they said they were. In other instances a higher degree of reliability may be required, for example if user presence is used to modify media access rights (e.g., share event photos only to people who attended the event). Location data can be obtained from a variety of sources such as, for example, a user's cell phone location, however, such sources taken singly may be insufficiently precise or of questionable, or unknown, reliability.